Subaru Forester blowing globes

Have you checked the voltage that is being applied to the lights.

Light globes can be quite sensitive to voltage, generally more so if voltage too high but can also apply to excessively low voltage.

Headlight ideal voltage is around 13.2 to 14 when measured at the globe with the engine running at about 1500rpm. Too high will be an Alternator fault, to low either alternator (check at rear of alternator) or undersize wiring (most likely). Measure the voltage ACROSS THE GLOBE, And also to earth.

Regards
Athol

CSeaJay
In my opinion, the only cause can be, far too high alternator regulated voltage, either constantly or intermittent. Never seen any earlier LC Toyotas blow globes with the 11 volts or so they apply to the headlights but plenty of globes blow with elevated voltages. Are the normal globes which have blown shiney on the inside glass? Not apparent with halogens headlight globes usually. Testing the alternator voltage would be the first thing to do. As mentioned above the voltage should be around that. Some replacement globes are rubbish and will not last anyway, maybe that is also a problem.
A ten year old Forester should have good quality globes from new, like Toyotas and Mazda have in the past, Those original globes lasted longer than many popular cars. This sounds like a stupid idea but is what I and a wrecker mate used to do, Use/source used globes from crashed cars of known quality brands and you don't have to replace globes for years to come, IF the voltage is correct. Hard to buy quality in todays world. How do you know what is what.
Also,
Your vehicle may have an intermittent connection of some wiring, ie, dirty loom plug or loose earth strap, which sometimes leaves the alternator, momentarily disconnected from battery and allowing the alternator reg to be, "unsensing" of battery voltage in that moment, and the resulting voltage spike WILL blow globes easily.

What kind of driving do you do? Lights constantly turned on as many people do these days on rough roads will test any bulb/globe.
Do your rear lights fail too?

Does the charge light come on before you turn the motor over, if not it is probably blown, without it working you will not get an indication if the alternator is faulty.

Check charge voltage as suggest, if lights flare when you rev the motor voltage regulator is most likely faulty or there is a problem with the voltage sensing circuit.

Thank you all, helpful comments.
It is a city car, no fault lights come on, and seem to be only the front lights.
Based on comments above I will check the alternator and the voltage at the lights
Thanks again

.
Hi CSeaJay,
There are really only two reasons for premature failure of lamps..... excessive mechanical vibration or excessive voltage.
I doubt that a Forester is "excessively vibrating" so it is likely to be over-voltage. Auto lamps are usually rated at 12-16 volts but will last longer when run at 12v rather than 16v.
If you can, apply a voltmeter to the headlamps and compare the voltage at idle and then at increased revs.

One reason for system over-voltage is a battery in poor condition where it has developed high internal resistance. Another very likely cause of excessive voltage being applied to your lamps is poor battery connection. If any of the battery connections, both positive or negative are less than 100% then the alternator will hold the car's wiring loom well above the nominal 12 volts and this high voltage will be applied to your lamps.
If this were the problem you will notice the headlamp brightness increasing as the engine is raised above idle speed. It would also show up as reduced starter performance.
If you suspect connection issues then remove and clean connections at both ends of the battery earth strap, both positive and negative battery posts, and all cable terminations to the positive battery connections.
Poor connections in the headlight wiring or at the lamps may cause lowered light levels but will not cause lamp failure.

One other possibility..... have you offended another driver wearing a black pointy hat? lol

It’s a Subaru thing

Great cars and fantastic reliability

My 2008 forester and I have 3 friends with 08-11 all suffer with failing globes. The dealerships offered no help or advise but were happy to replace them for a fee.

Just buy a dozen decent brand ones on eBay, you get quite proficient after a few goes especially on the drivers side because you have to remove the air duct.
Cheers
Mike

Ps. Just replaced the subie with a Honda ( wife’s decision)

Hi CSeaJay

I have a 2010 Forester and the problem will be as others have said high voltage. On my car when you turn the lights on the alternator voltage goes to over 14 volts. Good if you want to charge the battery quickly but a killer for 12 volt globes. I tried various headlamps and have had the most success with 'long life' globes which I think are from Phillips.

Cheers
David